<template>
<div>
  <div class="shopcart">
    <div class="content" @click="toggleList">
      <div class="contentleft" :class="{'highlight': selectFoods.length>0}">
        <div class="logowrapper">
          <div class="logo">
            <i class="icon-shopping_cart"></i>
          </div>
          <div class="num" v-show="selectFoods.length>0">{{totalCount}}</div>
        </div>
        <div class="price">￥{{totalPrice}}</div>
        <div class="desc">另需配送费￥{{seller.deliveryPrice}}元</div>
      </div>
      <div class="contentright">
        <div class="pay" :class="payClass" @click.stop.prevent="pay">{{payDesc}}</div>
      </div>
    </div>
    <div class="ball-container">
      <div v-for="(ball,index) in balls" :key="index">
        <transition name="drop" @before-enter="beforeEnter" @enter="enter" @after-enter="afterEnter">
          <div class="ball" v-show="ball.show">
            <div class="inner inner-hook"></div>
          </div>
        </transition>
      </div>
    </div>
    <transition name="fold">
      <div class="shopcart-list" v-show="listShow">
        <div class="list-header">
          <div class="title">购物车</div>
          <div class="empty" @click="empty">清空</div>
        </div>
        <div class="list-content" ref="listContent">
          <ul>
            <li class="food" v-for="(food,index) in selectFoods" :key="index">
              <span class="name">{{food.name}}</span>
              <div class="price">￥{{ food.price * food.count }}</div>
              <div class="cartcontrol-wrapper">
                <cartcontrol :food="food"></cartcontrol>
              </div>
            </li>
          </ul>
        </div>
      </div>
    </transition>
  </div>
  <transition name="fade">
    <div class="list-mask" v-show="listShow" @click.stop.prevent="hideList"></div>
  </transition>
</div>
</template>
<script>
import BScroll from 'better-scroll'
import cartcontrol from 'components/cartcontrol/cartcontrol'
export default {
  data() {
    return {
      balls: [
        {
          show: false
        },
        {
          show: false
        },
        {
          show: false
        },
        {
          show: false
        },
        {
          show: false
        }
      ],
      dropBalls: [],
      fold: true
    }
  },
  props: {
    selectFoods: {
      type: Array
    },
    seller: {
      type: Object
    }
  },
  computed: {
    totalCount() {
      let count = 0
      this.selectFoods.forEach((food) => {
        count += food.count
      })
      return count
    },
    totalPrice() {
      let price = 0
      this.selectFoods.forEach((food) => {
        price += (food.price * food.count)
      })
      return price
    },
    payDesc() {
      if (this.totalPrice === 0) {
        return `￥${this.seller.minPrice}元起送`
      } else if (this.totalPrice < this.seller.minPrice) {
        let diff = this.seller.minPrice - this.totalPrice
        return `还差￥${diff}元起送`
      } else {
        return '去结算'
      }
    },
    payClass() {
      if (this.totalPrice < this.seller.minPrice) {
        return 'not-enough'
      } else {
        return 'enough'
      }
    },
    listShow() {
      return !this.fold
    }
  },
  methods: {
    drop(el) {
      // 找出一个球去做动画
      for (let i = 0; i < this.balls.length; i++) {
        let ball = this.balls[i]
        if (!ball.show) {
          ball.show = true
          ball.el = el
          this.dropBalls.push(ball)
          return
        }
      }
    },
    beforeEnter(el) {
      // 入场动画开始前算出event.target的位置
      let count = this.balls.length
      // 如果不遍历球，是找不到我们刚才绑定的el对象的
      while (count--) {
        let ball = this.balls[count]
        if (ball.show) {
          let rect = ball.el.getBoundingClientRect()
          let x = rect.left - 32
          let y = -(window.innerHeight - rect.top - 22)

          el.style.display = ''
          el.style.webkitTransform = `translate3d(0, ${y}px, 0)`
          el.style.transform = `translate3d(0, ${y}px, 0)`

          let inner = el.getElementsByClassName('inner-hook')[0]
          inner.style.webkitTransform = `translate3d(${x}px, 0, 0)`
          inner.style.transform = `translate3d(${x}px, 0, 0)`
        }
      }
    },
    enter(el) {
      /* eslint-disable no-unused-vars */
      let rf = el.offsetHeight
      this.$nextTick(() => {
        el.style.webkitTransform = 'translate3d(0, 0, 0)'
        el.style.transform = 'translate3d(0, 0, 0)'
        el.style.transition = 'all .4s cubic-bezier(.49, -0.29, .75, .41)'

        let inner = el.getElementsByClassName('inner-hook')[0]
        inner.style.webkitTransform = 'translate3d(0, 0, 0)'
        inner.style.transform = 'translate3d(0, 0, 0)'
        inner.style.transition = 'all .4s linear'
      })
    },
    afterEnter(el) {
      let ball = this.dropBalls.shift()
      console.log('动画完成')
      if (ball) {
        ball.show = false
        el.style.display = 'none'
      }
    },
    // 促发购物车列表出现
    toggleList() {
      if (!this.totalCount) {
        return
      }
      this.fold = !this.fold
      // 实现列表滚动
      if (!this.fold) {
        // 利用nextTick的回调函数，让Dom列表刷新后再计算better-scroll的高度
        this.$nextTick(() => {
          if (!this.scroll) {
            this.scroll = new BScroll(this.$refs.listContent, {
              click: true
            })
          } else {
            // 重新计算better-scroll的高度
            this.scroll.refresh()
          }
        })
      }
    },
    hideList() {
      this.toggleList()
    },
    // 购物车的清空方法
    empty() {
      this.selectFoods.forEach(food => {
        food.count = 0
      })
      this.fold = true
    },
    pay() {
      if (this.totalPrice < this.seller.minPrice) {
        return
      }
      window.alert(`支付${this.totalPrice}元`)
    }
  },
  components: {
    cartcontrol
  }

}

</script>
<style lang="scss" scoped>
@import "../../common/scss/mixins";
.shopcart {
  position: fixed;
  bottom: 0;
  left: 0;
  z-index: 50;
  height: 48px;
  width: 100%;
  .content {
    display: flex;
    .contentleft {
      flex: 1;
      background-color: #141d27;
      .logowrapper {
        position: relative;
        display: inline-block;
        margin: 0px 18px;
        padding: 6px;
        top: -10px;
        width: 56px;
        height: 56px;
        background-color: #141d27;
        border-radius: 50%;
        box-sizing: border-box;
        .logo {
          width: 100%;
          height: 100%;
          border-radius: 50%;
          text-align: center;
          background: #2b343c;
          .icon-shopping_cart {
            font-size: 24px;
            line-height: 44px;
            color: #80858a;
          }
        }
        .num {
          position: absolute;
          top: 0;
          right: 0;
          width: 24px;
          height: 16px;
          line-height: 16px;
          text-align: center;
          border-radius: 16px;
          font-size: 9px;
          font-weight: 700;
          color: #fff;
          background-color: rgb(240, 20, 20);
          box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.4);
        }
      }
      .price {
        display: inline-block;
        font-size: 16px;
        margin-top: 12px;
        vertical-align: top;
        padding-right: 12px;
        box-sizing: border-box;
        border-right: 1px solid rgba(255, 255, 255, 0.1);
        color: rgba(255, 255, 255, 0.4);
        line-height: 24px;
        font-weight: 700;
      }
      .desc {
        display: inline-block;
        vertical-align: top;
        font-size: 10px;
        color: rgba(255, 255, 255, 0.4);
        line-height: 48px;
      }
      &.highlight {
        .logowrapper {
          .logo {
            background: rgb(0, 160, 220);
            .icon-shopping_cart {
              color: #fff;
            }
          }
        }
        .price {
          color: #fff;
        }
      }
    }
    .contentright {
      flex: 0 0 105px;
      background-color: #2b333b;
      .pay {
        font-size: 12px;
        color: rgba(255, 255, 255, 0.4);
        line-height: 48px;
        text-align: center;
        font-weight: 700;
        &.not-enough {
          background: #2b333b;
        }
        &.enough {
          background: #00b43c;
          color: #fff;
        }
      }
    }
  }
  .ball-container {
    .ball {
      position: fixed;
      left: 32px;
      bottom: 22px;
      z-index: 200;
      .inner {
        width: 16px;
        height: 16px;
        border-radius: 50%;
        background-color: rgb(0, 160, 220);
      }
    }
  }
  .shopcart-list {
    position: absolute;
    top: 0;
    left: 0;
    z-index: -1;
    width: 100%;
    transform: translate3d(0, -100%, 0);
    &.fold-enter,
    &.fold-leave-to {
      transform: translate3d(0, 0, 0);
    }
    &.fold-enter-active,
    &.fold-leave-active {
      transition: all 0.5s ease;
    }
    .list-header {
      height: 40px;
      line-height: 40px;
      padding: 0 18px;
      background-color: #f3f5f7;
      border-bottom: 1px solid rgba(7, 17, 27, 0.1);
      .title {
        float: left;
        font-size: 14px;
        color: rgb(7, 17, 27);
      }
      .empty {
        float: right;
        font-size: 12px;
        color: rgb(0, 160, 220);
      }
    }
    .list-content {
      padding: 0 18px;
      max-height: 217px;
      background: #fff;
      overflow: hidden;
      .food {
        position: relative;
        padding: 12px 0;
        box-sizing: border-box;
        @include border-1px(rgba(7, 17, 27, 0.1));
        .name {
          line-height: 24px;
          font-size: 14px;
          color: rgb(7, 17, 27);
        }
        .price {
          position: absolute;
          right: 90px;
          bottom: 12px;
          line-height: 24px;
          font-weight: 700;
          font-size: 14px;
          color: rgb(240, 20, 20);
        }
        .cartcontrol-wrapper {
          position: absolute;
          bottom: 6px;
          right: 0;
        }
      }
    }
  }
}
.list-mask {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 40;
  background-color: rgba(7, 17, 27, 0.6);
  backdrop-filter: blur(10px);
  &.fade-enter,&.fade-leave-to {
    opacity: 0;
  }
  &.fade-enter-active,&fade-leave-active {
    transition: all 0.5s;
  }
}
</style>
